Method and tool for cutting by deflagration dense materials



April 21, 1970 H. A. SEIB 3,507,230

METHOD AND TOOL FOR CUTTING BY DEFLAGRATION DENSE MATERIALS Filed Feb. 28, 1968 l 4 Sheets-Sheet 1 INVENTOR.

A ril 21, mm H. A. SEIB 3,5072% METHOD AND TOOL FOR CUTTING BY DEFLAGRATION DENSE MATERIALS 5 Filed Feb. 28, 1968 Apr l 1970 H. A. SEIB 3,507,230

METHOD AND TOOL FOR CUTTING BY DEFLAGRATION DENSE MATERIALS Filed Feb. 28, 1968 4 Sheets-Sheet 4 Fig i5 INVENTOR. Henry H. Se/b 'I/HTTORNEY United States Patent Int. Cl. F23b 7/00 US. Cl. 110-1 22 Claims ABSTRACT OF THE DISCLOSURE A deflagrating method and tool for cutting dense oxidizable materials such as metals as well as nonoxidizing materials such as rock or concrete by utilizing a burner pipe in which there is inserted a plurality of rods, at least fifty percent of the rods being of a low carbon iron bearing burnable metal, and as to which there may be applied aluminum rods not in excess of fifty percent of the rods to increase the effectiveness of the low carbon iron hearing rods. The rods are arranged in the burner pipe in such a manner as to insure a free flow of oxygen under pressure through the burner pipe and about the rods so that, upon ignition of the burnable rods at a free end of the burner pipe, the oxygen at the point of burning has the effect of supporting the combustion of the rods so that the carbon bearing iron rods burn vigorously with an intense heat to effect by defiagration a cutting action on the dense material subject thereto, and, during underwater operation, the oxygen under pressure flowing through the pipe prevents the surrounding water from entering the pipe while supporting the combustion of the rods; and including improved ignition means for initiating the combustion of the rods above and underwater.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to a deflagrating cutting method and tool of a type including a burner pipe which will gradually burn-oif upon ignition with a flame when oxygen is supplied thereto.

Description of the prior art Heretofore, as described in United States Letters Pat ent No. 1,494,003, issued May 13, 1924, to Leo M. Malcher, there has been disclosed a process and tool for piercing or cutting compact materials by utilizing two concentric pipes 10 and 11 of metallic irongand in an annular passage between the pipes a powdered flux 12, which may be composed of sodium carbonate, borax and common salt in equal proportions. The inner pipe 10 is connected by a flexible'tube 13 into an oxygen cylinder in such a fashion that oxygen may be delivered through the inner passage without displacing the flux. This flux with the burning of the iron pipes upon ignition furthers the piercing or cutting of the compact material by the decomposition thereof.

Furthermore, in United States Letters Patent No. 3,260,076, issued July 12, 1966, to Willi Humberg, there is disclosed a tubular cutting torch provided with a combustible material, the combustion of which is supported by oxygen provided at the tip of the torch. Moreover, in such a cutting torch, there is provided a burner pipe 1, which consists of steel and includes an insert consisting of a fusible wire-like core 13 of a magnesium alloy, such as Elektron. The core 13 of the Elektron is concentrically surrounded by a plurality of fusible steel wires each having a cross-sectional area smaller than that of the core 13.

These prior art patents fail to suggest the improved method and simpler idea of means of the present invenp CC tion for initiating and supporting combustion of the burnable rods above and underwater and in which through the provision of the low carbon bearing iron rods, together with the supporting blend of aluminum rods of the present invention, there is eliminated the flux and complex iron pipe arrangement disclosed in Malcher Patent No. 1,494,003, as well as the complex blends and mixtures of the fusible wire-like core 13 of a magnesium alloy, such as Elektron and fusible steel wires 14 of the Humberg Patent No. 3,260,076.

SUMMARY OF THE INVENTION The present invention resides in a method and tool which simplifies the more complex process and structures of the prior art references and provides a method and tool which accomplishes substantially the same result not only with a simpler structure, but at less expense.

An object of the invention is to provide a method and tool which will economically and efiiciently cut by defiagration dense oxidizable materials as well as dense nonoxidizable materials with greater speed and at less expense than the prior art processes and tools.

Another object of the invention is the provision of a method and tool to cut by defiagration dense oxidizable and non-oxidizable materials in which the defiagration may be initiated and maintained both above or underwater with a minimum of support equipment.

A further object of the invention is to provide, in the foregoing method and tool, a burner pipe including burnable metal rods particularly adapted for underwater defiagration in the supply of oxygen under sufiicient pressure to the interior of the burner pipe to prevent the surrounding water from entering the same while supplying sufiicient oxygen through the burner pipe to a free flame end of the pipe to efiectively support combustion at such end of the pipe and adjacent ends of the rods.

Another object of the invention is the provision of a solid fuel igniter means for initiating combustion of the burner pipe and burnable rods at a free end thereof.

A further object of the invention is to provide an igniter, including an operator-operative striker, for initiating combustion of the burner pipe and burnable rods at above and underwater with a minimum of support equipment.

Another object of the invention is the provision of a stand for carrying a multiplicity of the burner pipes in an operative relation to a material to be simultaneously cut by defiagration through a joint action of the several burner pipes.

A further object of the invention is to provide a burner pipe including iron rods having a carbon content in a range such that, upon a flow of oxygen through the burner pipe and along the carbon bearing iron rods, there is effective upon igntion of the rods at the free end of the burner pipe a flame which is locally limited and of such a high temperature as to effect a cutting by a thermal process of dense elements or combinations of elements.

Another object of the invention is the provision of a metal rod for use in such a tool and a rod burnable under a supply of oxygen, the rod consisting of between eight percent and eighteen percent carbon and the balance of iron.

A further object of the invention is to provide an improved iron bearing burner pipe including within its interior a plurality of low carbon iron rods bearing a range of from eight to eighteen percent carbon and in which the burner pipe serves as a conduit for oxygen to support combustion of the carbon bearing iron rods at a free end of the burner pipe so as to provide an intense heat as the burner pipe and carbon bearing iron rods are consumed to effect a cutting by defiagration of dense materials.

Another object of the invention is the provision of a,

burner pipe assembly including within the interior of a burner pipe a plurality of rods, at least fifty percent of the rods being of a low carbon iron bearing a range of from eight to eighteen percent carbon and the remainder of the rods not in excess of fifty percent of the total number of rods containing ninety-five percent or better pure aluminum to substantially increase the deflagration effect of the low carbon bearing iron rods in the burner pipe assem-bly.

These and other objects and advantages of the invention are pointed out in the following specification in terms of the embodiment thereof, which is shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only and are not a definition of the limits of the invention, reference being had to the appended claims for this purpose.

DESCRIPTION OF THE DRAWINGS In the drawings, in which corresponding parts have been indicated by like numerals:

FIGURE '1 is a side elevation view of a cutting tool embodying the present invention in an assembled relation;

FIGURE 2 is an enlarged longitudinal sectional view, taken along the line 22 of FIGURE 1, looking in the direction of the arrow, and showing the supporting head of the cutting tool in an assembled relation with the burner pipe, and extending longitudinally within the interior of the burner pipe the carbon bearing iron rods of the present invention; 1

FIGURE 3 is an enlarged sectional view taken substantially along the line 3-3 of FIGURE 2, looking in the direction of the arrows, showing the arrangement of thecarbon bearing iron rods in the improved burner pipe of the present invention, which permits a free flow of oxygen through the burner pipe and along the carbon bearing ir'on rods in the spaces therebetween;

FIGURES 4, and 6 are enlarged sectional views of a burner pipe assembly showing modified arrangements of the carbon bearing rods of FIGURE 3 and showing in FIGURE 4 a central aluminum rod; in FIGURE 5 two aluminum rods; and in FIGURE 6 three aluminum rods in each instance substituted for corresponding low carbon bearing iron rods in the assembly of FIGURE 3 to substantially increase the detlagration effect of the burner pipe assembly;

FIGURE 7 is enlarged sectional view of a burner pipe assembly showing another modification in the provision of an aluminum tubular pipe in place of the black iron burner pipe of the assembly of FIGURE 3 to increase the deflagration effect of the burner pipe assembly and provide greater flexibility and versatility in the use of such tool;

FIGURE 8 is a side elevation view of a stand for supporting a multiplicity of the burner pipes in an operative relation to a cement wall;

FIGURE 9 is a front view of the stand shown in FIGURE 8; 7 FIGURE 10 is a front view of a modified form of a stand for supporting a multiplicity of the burner pipes in an operative relation for cutting by defiagration a circular opening in an oxidizable or non-oxidizable material;

FIGURE 11 is a side elevation view of the stand shown in FIGURE 10, showing the stand supporting the multiplicity of burner pipes in an operative relation for cutting by deflagration the circular opening in a cement wall;

FIGURE 12 is an enlarged fragmentary longitudinal sectional view of the burner pipe assembly illustrated in FIGURE 3 with one form of an igniting means operatively connected at the free end of the burner pipe;

FIGURE 13 is an enlarged fragmentary longitudinal sectional view of the burner pipe assembly with a modified form of igniting means operatively connected at the free end of the burner pipe; and

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring now to the drawings and particularly to FIG- URE 1, there is shown a cutting tool embodying the present invention and including a black iron burner pipe 5 of any desired length and having a longitudinally extending bore 6. The burner pipe 5 has an end portion that may be replaceably fitted within a supporting head 7 and a knurled handle portion 9 to be gripped by the hand of the operator.

The supporting head 7 has a conduit end portion 11 connected through a valve 13 to a suitable flexible tube 15, leading to a pressurized oxygen supply tank 17. The valve 13 has a valve control handle 19' arranged in a conventional manner so that an operator may position the handle 19 to open and close the valve 13 to control the flow of oxygen from the tank 17 into the handle 9. The oxygen may flow through the handle 9 into an open end 20 of the burner pipe 5 and along the longitudinally extending bore 6 and out an opposite open free end 21 of the burner pipe 5.

Referring now to FIGURE 2, there is shown a clamping member 23 of an elastically deformable material, such as hard rubber, inserted into a hollow cylinderical member 25 of the supporting head 7. The clamping member 23 is provided with a longitudinally extending central bore 27 for receiving an end portion of the burner pipe 5. At an inner end of the clamping member 23, there is disposed a washer 29 positioned between an inner surface of a tapered end portion 31 of the cylindrical member 25, and the inner end of the clamping member 23. The washer 29 has an inner angular cam surface 33 upon which there bears the inner end surface of the clamping member 23. An opposite end of the clamping member 23 has a convex surface 35, which fits in a concave end surface 37 provided in an end portion 39 of the handle 9, which is positioned within the cylindrical member 25.

There is provided in the end portion 39 of the handle 9 external screw threads 41 arranged to threadingly engage internal screw threads '43 formed in an end portion of the cylindrical member 25 of the supporting head 7.

Thus, upon the end portion 39 of the handle 9 being screw threadingly engaged in the cylindrical member 25, the clamping member 23 is axially compressed between the concave end surface 37 of the handle 9 and the angular cam surface 33 of the washer 29 so as to tightly clamp an end portion of the burner pipe 5 within the central bore 27 of the clamping member 23 due to a resulting simultaneous radial deformation of the elastically deformable material of the clamping member 23.

Due to this deformation, the cylindrical outer surface of the clamping member 23 is pressed against the internal wall of the hollow supporting head 7 while the wall of the longitudinally central bore 27 of the clamping member 23v is pressed around the end portion of the burner pipe 5 so as to secure and seal the end of the burner pipe 5 in the supporting head 7 and handle 9.

The assembly is further secured in position by a collar 45, having internal screw threads 47 adapted to secure threadingly engage with external screw threads 49 providedjin an outer end portion of the cylindrical member 25 The collar 45 is tightly threaded on the end portion of the cylindrical member 25 so as to secure the assembly in position.

The burner pipe 5 is formed of black iron and includes the longitudinally extending bore 6 in which there is inserted a plurality of longitudinally extending burnable low carbon bearing iron rods 52, forming a principal feature of the present invention.

It has been found that, for the successful operation of the invention, the burnable rods 52 should have a carbon content by weight of between eight percent and eighteen percent, both inclusive, with a balance substantially of non.

In operation, oxygen is fed under pressure from the supply tank 17 through the pipe 15 and the open valve 13 into the conduit 11 and through the handle 9 into the open end 20 of the attached portion of the burner pipe 5 so as to flow through the longitudinal bore 6 of the pipe 5 and along the spaces between the longitudinally extending burnable rods 52 to the free open end of the pipe 5.

The ends of the rods 52 may be first brought to their ignition temperature in oxygen by means of heat generated by an actylene torch, the valve 13 being adjusted by the operator so that a slow stream of oxygen is maintained through the inner bore 6 of the burner pipe 5 during such heating. When one or more of the carbon bearing iron rods 52 ignite, the burner pipe 5 is placed against the material to be cut at the point where the cutting is desired, and the valve control handle 19 is there.- upon positioned by the operator so that the supply of oxygen is increased to a quantity to sustain vigorous deflagration of the end portions of the carbon bearing rods 52 and the end portion 21 of the burner pipe 5 adjacent thereto, which gradually burns-off when ignited under the supply of oxygen.

The burning of the iron burner pipe 5 and carbon bearing iron rods 52 liberates a large quantity of heat and, by utilizing a suitable pressurized source of oxygen 17 for supplying a flow of oxygen through the burner pipe 5, both the end portions of the black iron burner pipe and the carbon bearing iron rods 52 will oxidize at a rapid rate and generate sufficient heat to cut by melting or defiagration almost any known material. Thus, when the free end 21 is ignited, a flame will result, the intensity of which is adaptable to actual requirements by varying the size of the burner pipe 5 and the number and size of the rods 52.

The number of carbon content rods 52 inserted in the burner pipe 5 is dependent upon the inner diameter of the burner pipe 5. The diameter of the rods 52 for average use is not significant. It is desirable, when cutting nonoxidizing materials, such as rock or concrete, to provide the rods 52 of a relatively small diameter so that in burning the rods 52 of the smaller diameter will give off more units of thermal energy and increase the effectiveness thereof in the cutting of such non-oxidizable materials. However, when cutting oxidizable materials, such as metals, the rods 52 are provided of a relatively large diameter so as to work faster, because more oxygen is then delivered at the point of burning, which has the effect of causing the oxidizable metal material of the work piece to support the combustion and defiagration.

MODIFIED FORMS OF THE INVENTION It has been found that the speed of penetration through concrete, rock or other non-combustible materials can be substantially increased by the substitution, as shown by FIGURES 4, 5 and 6, of one or more rods 60 containing ninety-five percent by weight or better of pure aluminum for an equal number of the low carbon iron bearing rods 52, shown by FIGURE 3.

There is an increase, however, in the cost of the modified form of construction of the cutting tool of FIG. URES 4, 5 and 6 and 7, because of the higher cost of the aluminum material in the construction thereof, and because of the further fact that such modified form of cutting tool requires a higher oxygen flow for sustaining optimum combustion which results in a higher operating cost of the modified forms of the tool of FIGURES 4, 5, 6 and 7.

However, in comparing the operating characteristics of the several forms of the cutting tool of FIGURES 3, 4, 5, 6 and 7, it has been found that, when using the cutting tool of FIGURE 3 to pierce holes in concrete, rock and other non-combustible materials, such a cutting tool, in which the low carbon iron bearing rods 52 are positioned within a black iron burner pipe 5, having a diameter of three-eighths of an inch /8"), will pierce a ten inch (10") thick concrete wall with a hole having a diameter of about one and one-half inches (1%") in about two minutes and four seconds; while with the substitution of one of the aluminum rods 60 for one of the low carbon iron bearing rods 52, as shown by FIGURE 4, such modification of the tool will effect a marked increase in the speed of operation of the tool so as to decrease the time required to effect a penetration of the wall by the tool through deflagration, while at the same time the diameter of the hole effected by the modified form of such tool will be increased as hereinafter explained.

With the substitution of two aluminum rods 60 for two jof the low carbon iron bearing rods 52, as shown by FIGURE 5, the time for penetration of the wall by the tool'will remain about the same, but the diameter of the hole effected by the penetration will be further increased. Substituting three aluminum rods 60 for three of the low carbon iron bearing rods 52, as shown by FIGURE 6, will .further increase the diameter of the hole effected in the penetration of the concrete wall.

A blend of fifty percent (50%) aluminum rods 60 and fifty percent (50%) low carbon bearing iron rods 52 will effect a further increase in the diameter of the hole effected in penetrating the concrete wall by the tool through defiagation.

It may also be desirable in some applications to use a pipe 65, as shown in FIGURE 7, of ninety-five percent by weight or better of pure aluminum in place of the black iron burner pipe 5 and to include in the aluminum pipe 65 the low carbon iron bearing rods 52, as shown by FIGURE 7. This arrangement will also effect basically the improved results aforenoted. Moreover, inasmuch as the aluminum pipe 65 will be more flexible than the black iron burner pipe 5, such tool would have particular application where existing fixtures might obstruct a direct line of penetration. Thus, should it become necessary to cut behind or around an obstruction, which is to remain standing, there is a definite advantage in a less rigid tool, such as shown by FIGURE 7, which will bend due to the flexibility of the aluminum pipe 65, but which tool would still be stiff enough due to the low carbon iron bearing rods 52 in the pipe 65 to allow the application of pressure. Although production costs of the modified form of the tool of FIGURE 7 would be higher than the tool of FIGURE 3, because of a higher cost of the aluminum material to be used in the pipe 65, it will be obvious that, in a specialized application, it would be feasible to use such a tool, as shown by FIGURE 7.

Moreover, it will be apparent from the foregoing discussion of the forms of the invention that, as illustrated by FIGURES 3, 4, 5, 6 and 7, the capability of the tool to vary the diameter of the penetration hole by changing the percent of aluminum rods 60 to the low carbon iron bearing rods 52 increases materially the versatility of the tool and furthermore may decrease the cost in some cases of doing certain work which would otherwise be very difficult or expensive.

Ithas been found, however, that there is a limit to the range of substitution of aluminum rods 60 for the low carbon iron bearing rods 52 and that the tool will not operate satisfactorily when the percentage of the aluminum rods exceeds fifty percent (50%). When the percentage of the aluminum provided by the rods 60 exceeds the fifty percent (50%) limit, the flame of the tool will become extinguished. Thus, as a practical matter, the rods in the black iron burner pipe 5 must include at least fifty percent (50%) low carbon bearing iron. such as the rods 52, and not more than fifty percent (50%) of aluminum, such as the rods 60, should be included therein. Obviously, the rods 52 of the low carbon iron bearing material provide at least fifty percent (50%) of the material by weight of all of the rods arranged inside of the burner pipe 5.

The following are typical examples of the composition of the respective rods that may be applied in the present invention to a black iron burner pipe 5, having a diameter of three-eighths of an inch and the time which it has been found would be required by such a cutting tool to penetrate by deflagation a ten inch (10") thick poured concrete Wall, using oxygen under a pressure of one hundred pounds per square inch applied through the burner pipe so as to support combustion at the free end 21 thereof:

Length Hole Time to Bar composition consumed diameter penetrate 14 low carbon iron bearing rods 5.2 1% 2 min. 4 sec.

13 low carbon iron bearing rods 4,25 1% 1 min. 37 sec.

and 1 aluminum rod.

12 low carbon iron bearing rods 4.85 1% 1 min. 37 sec.

and 2 aluminum rods.

low carbon iron bearing rods 5.15 2 1 min. 37 sec.

and 3 aluminum rods.

5 low carbon iron bearing rods 6.05 2 /t 2 rnins.

and 5 aluminum rods.

In a comparison of the foregoing operating characteristics of the black iron burner pipe 5, including rods having the aforenoted compositions, it has been found that an aluminum burner pipe tubing, such as indicated in FIGURE 7 by the numeral 65, having a diameter of onehalf inch /2") and including only low carbon iron bearing rods, such as the rods 52 of FIGURE 7, under identical conditions would have the following operating characteristics:

Length Hole Time to Bar composition consumed diameter penetrate 36 OD. aluminum tubing 10.3 1" 4 min. 40 sec.

low carbon iron bearing rods.

The cutting tool of the present invention provides extremely high operating temperatures in excess of six thousand degrees Fahrenheit (6,000 R), which are sufiicient to efiect by deflagration the cutting and penetration of the following dense materials, having the indicated melting temperatures set oppositely thereof:

Material: Melting temperature, F.

There is thus provided a method and tool for economically cutting oxidizable and non-oxidizable materials by deflagration faster and at less expense than in the prior art and by means of a cutting tool of a simplified structrue.

UNDERWATER OPERATION The tool of the present invention works equally as well when it is completely submerged in water as above the the water or ground level. This is true because, when the tool is submerged in Water, the oxygen supplied under pressure and flowing through the interior of the burner pipe 5 and along the spaces between the longitudinally extending rods 52, or rods 52 and 60, to the free open end 21 of the pipe 5 applies sufficient oxygen under pressure to keep the surrounding Water out of the pipe 5 and to supply sufficient oxygen to support the combustion of the flame end 21 of the burner pipe 5.

This underwater Operating capability of the tool of the present invention is extremely beneficial in any underwater demolition Work. The prior tools available to do this kind of underwater work are primarily electric are types, which are very dangerous and hazardous because of the ever present danger of electrocution of the operator-diver. The use of an underwater oxy-acetylene type cutting tool is limited as to thickness of cut, and such oxygen-acetylene type tool cannot be used at any water depth because of the water pressure. Acetylene will explode at a water pressure of approximately twenty-five (25) pounds per square inch. While oxygen-hydrogen type torches will work at deeper water depths, these type torches require extensive surface support equipment and are much more expensive to operate. The simple cutting tool of the present invention avoids these disadvantages of the prior cutting tools available for underwater operation and demolition work.

FURTHER MODIFIED FORMS OF THE INVENTION In a further modified form of the invention, there may be provided, as illustrated in FIGURES 8 and 9, a stand forcarrying a series of the burner pipes 5, such as heretofore described with reference to FIGURES 1, 2, 3, 4, 5, and 6.

The stand 100', as illustrated in FIGURES 8 and 9, includes a base 102 from which there projects a pair of vertically extending supporting members 104 and 106 carrying a top plate 108. The supporting member 104 has provided therein horizontal openings 111, 112, 113, 114 and arranged in alignment with corresponding openings 111A, 112A, 113A, 114A and 115A provided in the supporting member 106.

The respective openings in the supporting members 104 and 106 are so arranged as to carry a series of burner pipes 5, as shown by FIGURES 8 and 9. The free ends of the burner pipes 5 after ignition are placed adjacent to a concrete wall in which an opening is to be formed by causing the burner pipes 5, as heretofore explained with reference to FIGURES 1 to 6, to burn a series of holes 111B, 112B, 113B, 114B and 11513 in the concrete wall 120, as in the line drill method and then pulling or removing the center plug.

Thus, instead of burning one hole at a time in the cutting of an opening, in the present invention through the provision of the simple stand 100 the burner pipes 5 are maintained in a parallel relation with the free burner ends 21 thereof immediately adjacent the concrete wall 120 and in the holes formed thereby at all times.

While it is necessary to use a higher capacity oxygen regulator in the operation of the multiple burner pipes 5, it has been found that by the use of multiples of the burner pipes 5 at the same time to effect the desired opening, the labor savings are very considerable and real.

In the modified form of the stand 150, shown by FIGURES 10 and 11, there is provided a base 152 from which there projects a pair of vertically extending supporting members 154 and 156 carrying a top plate 158. The supporting member 154 has provided therein horizontal openings arranged in alignment with corresponding openings 161A, 162A, 163A, 164A and 165A provided in the supporting member 156 and arranged in a circular pattern, as best shown in FIGURE 10.

The respective openings in the supporting members 154 and 156 are so arranged as to carry a series of burner pipes 5, as shown by FIGURES 10 and 11. The free ends 21 of these burner pipes 5 after ignition are placed adjacent to a concrete wall 170 in which a circular opening is to be formed by causing the burner pipes 5, as heretofore explained with reference to FIGURES l to 6, to form by deflagration a series of five holes, three of which have been indicated in FIGURE 11 by the numerals 161B, 164B and 165B, and which holes are arranged in a circular pattern. The web of material remaining between the several holes in the circular pattern may be broken out to complete the circular opening in the wall. More or less burner pipes 5 may be utilized, but, in any case, the labor saving factor is in direct relationship to the total number of the burner pipes that may be utilized at the same time.

Connector ends of the pipes 5 may be threaded, and by using standard threaded couplings 175, as illustrated in FIGURES 8 and 11, multiple lengths of the pipe 5 may be fastened together so that sufiicient burner pipe material may be supplied to enable each burner tool to burn through the concrete wall on one set up, thereby avoiding the necessity of a shut-down and restart in the burner operation. This also eliminates the need to reheat the slag from the prior consumed burner pipe, which may be present with the attendant loss of time and expense.

MODIFIED IGNITING MEANS In a modified form of the invention, instead of utilizing the heat generated by an acetylene torch to ignite one of more of the carbon bearing iron rods 52 of the tool, there is provided a modified form of igniting means, as shown by FIGURES 12, 13 and 14, to shorten the ignition time, reduce the amount of support equipment necessary, simplify the ignition procedure and in general increase the versatility of the tool of the present invention.

In the modified form of the ignition means illustrated in FIGURE 12, there is provided a plug 180 of a solid ignition fuel of a type well known in the art, such as heretofore utilized as rocket fuel. The plug ignition fuel 180 is carried in a suitable plastic or metal canister 182 of a size and shape adapted to fit snugly over the forward open end portion 21 of the burner pipe 5 with the solid ignition fuel 180 being positioned immediately adjacent to the free ends of the rods 52 of FIGURE 3 or rods 52 and 60 of FIGURES 4, 5 and 6.

A primer cord or fuse 185 extends through an outer end 187 of the canister 182 into the solid ignition fuel 180, as shown by FIGURE 12, so that by igniting the fuse 185 by conventional means, exteriorly of the canister 182, the solid fuel 180 therein may be ignited through the operation of the fuse 185. The solid ignition fuel 180 may be of a conventional type and is of a type effective upon ignition to generate sufiicient heat, in excess of six thousand degrees Fahrenheit (6,00 F.), to preheat the tip 21 of the burner pipe and burner rods 52 or 52 and 60 to a point at which combustion will take place and continue.

As shown by FIGURE 12, the use 185 may be placed so as to extend through the outer end 187 of the canister 180 or, as shown by FIGURE 13, a fuse 189 may extend through an opposite end or skirt portion 191 of the canister 182 into the solid ignition fuel 180 at a point immediately adjacent the free ends of the rods 52 or 52 and 60 at the end 21 of the burner pipe 5 so that the resultant heat generated by the ignition fuel 180 may be applied to the ends of the rods for a slightly longer time, which is advantageous in assuring that combustion takes place at the end 21 of the burner pipe 5 and bars 52 or 52 and-60, as heretofore explained.

In a further modified form of the invention, as shown by FIGURE 14, there is provided a conventional type striker 195, which fits over the free end of the canister 182 and includes a pull cord 197 adapted to be manually actuated by the operator to cause the striker 195 in a manner well known in the art to ignite the solid ignition fuel 180, causing combustion to take place at the end 21 of the burner pipe 5 and rods 52 or 52 and 60.

The form of the invention illustrated by FIGURE 14 is especially desirable in underwater work since no support equipment is required to light the fuse or ignite the ignition fuel to effect combustion at the free end 21 of the burner pipe 5 and rods 52 or 52 and 60.

Actuation of the pull cord 197 of the striker to initiate the combustion may be effectively carried out during underwater demolition work by a diver or operator while completely submerged in the water with the tool. The canister 182 and the parts of the tool would, of course, be coated with a suitable waterproof plastic and protected from the effects of the water by suitable waterproofing means for optimum advantages in the underwater operation.

Although several embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the present invention. Reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What I claim is: v

1. In an open flame torch of a type including an elongated burner pipe having an inner surface, an outer surface and an axis, said pipe being made from a metallic material which gradually burns-off when ignited under a supply of oxygen, a plurality of elongated burnable rods, said burnable rods having substantially the same length as said pipe and being arranged inside of said pipe substantially parallel to said axis and with their surfaces at least in part spaced from said inner surface and from each other, so as to define a passage means through said pipe from one open end to an opposite open free end, oxygen supply means, and connecting means interposed between the one open end of said pipe and said oxygen supply means for connecting said one open end of said pipe to said oxygen supply means, whereby said oxygen may be supplied through said passage means to the opposite open free end of the pipe, and end portions of the burnable rods adjacent the open free end of the pipe for ignition under the supply of oxygen; the improvement comprising said burnable rods being of an iron bearing material having a carbon content such as to support dcfiagration of the end portions of the rods adjacent the open free end of the pipe upon ignition thereof under the oxygen supplied thereto through the passage means.

2. The improvement defined by claim 1 in which said burnable rods consist of not less than eight percent by weight of carbon and the balance substantially of iron.

3. The improvement defined by claim 1 including at least one other rod having substantially the same length as said pipe and being arranged inside of said pipe substantially parallel to said axis and with a surface at least in part spaced from said inner surface of the burner pipe and from said rods of an iron bearing material having a carbon content, said other rod being of an aluminum bearing material to increase the defiagration effect at the open free end of the pipe.

4. The improvement defined by claim 1 including said burner pipe containing at least ninety-five percent aluminum to increase the deflagration effect of the rods of an iron bearing material having a carbon content in supporting the defiagration at the open free end of the pipe and to provide flexibility in the use of the burner pipe.

5. The improvement defined by claim 1 including a solid fuel igniter, means positioned on the free end of the pipe to initiate the ignition of the end portions of the burnable rods adjacent the free end of the pipe.

6. The improvement defined by claim 1 including an igniter means positioned at the free end of the pipe to initiate the ignition of the end portions of the burnable rods adjacent the free end of the pipe, the igniter means including a striker, and an operator-operative means for the striker to render the igniter means effective.

7. The improvement defined by claim 1 in which said burnable rods consist of not more than about eighteen percent by weight of carbon and the balance substantially of iron.

8. The improvement defined by claim 1 in which said burnable rods consist of between about eight percent and about eighteen percent by weight of carbon and the balance substantially of iron.

9. The torch defined by claim 1 for use in underwater defiagration, including the oxygen supply means providing a flow of oxygen through the passage means to the open free end of the burner pipe at a pressure sufiicient to prevent surrounding water from entering the pipe and suflicient to support combustion at the free end of the pipe.

10. The improvement defined by claim 3 in which said rods of an iron bearing material having a carbon content providing at least fifty percent of the material of all of the rods arranged inside of said pipe.

11. The improvement defined by claim 8, including at least one other rod having substantially the same length as said pipe and being arranged inside of said pipe substantially parallel to said axis and with a surface at least in part spaced from said inner surface of the burner pipe and from said rods of an iron bearing material having a carbon content, said other rod containing at least ninety-five percent aluminum by weight and being arranged to increase the defiagration effect of the rods of an iron bearing material having a carbon content in supporting defiagration at the open free end of the pipe.

12. The invention defined by claim 8, including a plurality of other rods having substantially the same length as said burner pipe and being arranged inside of said pipe substantially parallel to said axis and with their surfaces at least in part spaced from said inner surface of the burner pipe and from surfaces of the rods of an iron bearing material having a carbon content, said other rods containing at least ninety-five percent by weight of aluminum and being so arranged in the burner pipe as to increase the defiagration efiect of the rods of an iron bearing material having a carbon content in supporting the deflagration at the open free end of the pipe, and said iron bearing rods providing at least fifty percent of the material of all of the rods arranged inside of said pipe.

13. The combination defined by claim 9 for use in underwater deflagration including a solid fuel igniter means, a canister mounted at the free end of the burner pipe and supporting the solid fuel igniter means immediately adjacent the end portion of the burnable rods, and means to ignite the solid fuel to initiate ignition of the end portions of the burnable rods under the support of the oxygen supplied thereto through the passage means in the pipe.

14. The improvement defined by claim 12 in which said rods of an iron bearing material having a carbon content provide at least fifty percent of the material of all of the rods arranged inside of said pipe.

15. The combination defined by claim 14 for use in underwater defiagration in which the means to ignite the solid fuel includes a striker, an operator-operative pull cord to render the striker effective to ignite the solid fuel, and the operator-operative pull cord being arranged for manual operation by an operator while completely sub merged underwater with the torch and igniter means.

16. In a burner pipe, a plurality of metal rods burnable under a supply of oxygen applied through said burner pipe, each of said rods consisting of between about eight percent and about eighteen percent by weight of carbon and the balance of iron, a plurality of other metal rods within said burner pipe, said other metal rods containing at least ninety-five percent by weight of aluminum for supporting deflagration by the iron bearing rods at an open free end of the burner pipe, and said iron bearing rods providing at least fifty percent of the material of all of the rods within the burner pipe.

17. A method for cutting by defiagr-ation a dense material which comprises inserting a plurality of relatively low carbon content iron rods within an iron pipe, supplying oxygen through the pipe and along the rods to an open free end of the pipe, then igniting the end portions of the rods adjacent the free end of the pipe under the oxygen supplied thereto through the pipe so as to provide an intense heat causing the free and portion of the iron pipe and the adjacent end portions of the carbon bearing iron rods to be gradually consumed, and applying the ignited free end of the pipe to the dense material to effect a cutting by deflagration of said dense material.

18. The method defined by claim 17 in which said rods consist of not less than about eight percent by weight of carbon and the balance substantially of iron.

19. The method defined by claim 17 in which said rods consist of not more than about eighteen percent by weight of carbon and the balance substantially of iron.

20. The method defined by claim 17 in which said rods consist of between about eight percent and about eighteen percent by weight of carbon and the balance substantially of iron.

21. The method defined by claim 17, including the step of inserting at least one other rod of an aluminum material within said iron pipe to increase the cutting effect by deflagration of the ignited free end of the pipe.

22. The method defined by claim 21 in which said iron rods provide at least fifty percent of the material of all of the rods within said iron pipe.

References Cited UNITED STATES PATENTS 2,210,640 8/1940 Swaiford 2l970 2,496,863 2/1950 Dechamps et a1. 123 XR 2,819,502 H1958 Snyder et al. 75-123 XR 3,260,076 7/1966 Humberg 431-99 KENNETH W. SPRAGUE, Primary Examiner U.S. Cl. X.R. 431-99 

